BRIEFLY

Contel Corp. said that it will write off up to $200 million in the fourth quarter to pay off long-term debt and restructure its ailing ASC subsidiary, formerly American Satellite Co. The Atlanta-based telecommunications company said the restructuring was triggered by a substantial decline in use of ASC's national satellite network because of increased competition and changing technology. The moves should reduce Contel's 1987 earnings by between $108 million and $120 million, company officials said.